Cable connecter



J. C. LEDBETTER CABLE CONNECTEB Filed Jan. 22. 1924 INVENTOR James C ledefler' Patented Oct. 4, 1927.

U-NITED" STAT-ES PATENT OFFICE.

JAMES C. LEDBETTER, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE THOMAS & BETTS 00., OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEWJERSEY.

CABLE CONNECTER.

Application filed January 22, 1924. Serial No. 687,776.

This invention relates to combination outlet boxes andcable connecters, and more particularly to improvements in connecters for use in anchoring electric cables or conduits to electric box fixtures, such as outlet boxes, switch boxes, cable boxes, and the like.

An object of the invention is to produce an improved cable connecter of simple structure capable of being manufactured at low cost, and which positively functions to securely fasten a cable to said box, as well as produce a cable connecter which fits standard round knockout holes in boxes of pres ent-day use; and an important feature of my connecter invention resides in'the two part construction together with. the ability thereof to cover over the box opening by closely surrounding the cable.

A further object of the invention is to produce a simple plate and shell connecter structure embodying two plain stampings which, when'assembled with clamping means, such as a screw, the said connecter functions to simultaneously fasten a cable as well as anchor itself to a box. For this purpose the connecter employs one'operating means and is so formed that the box hole edge is ex posed directly to the cable.

The accompanying drawing illustrates an embodiment of the invention serving to illustrate the principle and structure thereof as well as the mode of operation; and the connecter may be subject to modifications in certain respects without departing from the scope and principle of the invention.

Figure 1 shows a top open view of an electric fixture box joined to a cable through the agency of an improved connecter constituting the important part of this invention; and Figure 2 shows a side view thereof.

Figure 3 illustrates a sectional view taken on the line 33 ofthe drawing; and Figure at shows a sectional view takenon the line 44 of the drawing.

Figure 5 illustrates a cluster view of the two-part connecter constituting an important part of this invention, the said view illustrating rear, side, and top projections of the connecter.

The last three figures of the drawing illustrate a slightly modified structure in which substantially the same principle of the invention is involved.

Figure 6 shows a longitudinal section view through a box with the two connecter parts in section 'mounted opening.

Figure 7 is a sectional View on the line 77 and Figure 8 is a sectional view on the line88 To those conversant with the art, it is appreciated how present-day boxes B are ordinarily made with standard round knock-out holes H into which the cable C carrying wires W is fastened by connecters; and as aforesaid it is one of theprincipal objects of this invention to produce simple'and inexpensive connecters for fastening the cable in the box knock-out opening.

With particular reference to the construction of the connecter itself, it is explained that this connecter is preferably constructed in two separable parts each of which is provided with box hole edge anchorage means as notches or grooves which overlap and engage the box knock-out opening thereby holding the parts in spaced relation, and the cable C is inserted thereinbetween after which a clamping or operating device, such as a screw, impinges the cable to lock all parts together.

The two connecter parts are made with companion cover plates 10 and 11 such that when brought together and assembled in the box, the two said plates provide a cover 101l fitting substantially tight and close over that portion of the knock-out opening H of the box which is not covered up by the cable C. Furthermore, each co-operating cover platelO and 11 is made with a substantially half-round or arcuate opening 12 through which the cable C passes when the parts are assembled. The two. plates 10 and 11 rest or abut one side of the box B and embrace the circular wall of the cable to cover up thebox opening H as aforesaid. r

A cable rest or sleeve in the form of an arcuate Wall or in the form of a substantially half-round projecting part or shell 13 is made integral with one cover plate, and in in the box knock-out this instance the part 13 is integral with the plate 11 andv has its circular wall 13 coincidently formed with the arcuate opening 12 made in the said plate 11. A bushing rim 14 is made on the outer end of the supporting shell or sleeve part 13 and the cable end C stops or rests against this bushing when the parts are assembled.

The sleeve or shell 13 is disposed inside the box and held in position by a plate or g whi h pr je ts ug the b x sp ning. This lug or plate is made witha pair of oppositely punched or formed box hole edge grooves or notches 16, the said notches being formed in the plate 15 adjacent the plate 11 such that the box wall 13 fits in the notches 16 and abuts the surface of the cover plate 11. By introducing the plate part 15 through the box hole H, the-notches 16v are readily engaged over the edge of the box hole thereby positively holding the part n P a e- The other part of the connecter may also comprise a cover plate element 10 .asfhereinbefore described and the said plate includes a'screw supporting end 18. similar to .the one hereinbefore described. The plate 10 and end or lug 18 are formed substantially at right angles and box edge notches 19. are formed in, the. lug 18 adjacent the cover plate '10, there, being two notches 19 oppositely arranged as shown. A pressure or clamp screw 20, is. threaded through the lug 18 and preterably to one. side thereof which auses e re mp n e an c ew to the. cable C at substantially a tangent there, to, thus avoiding crushing the cable.

h hole e ge not h s; nd '9 formed in the separable connecter parts serve to hold the two cover plates 10 and 11 in alignment close to the box wall surface when the parts are assembled. It is important to note that the. width of the two projecting lugs or plates 15, and :18 is. somewhat less than the diameter of the'knock-out hele i t e bo TW prei n pa 1 5, and18 being substantially small in size are readily projected through the box; openg, .pr e iab y' e a a t me when m t a sem ng t e pa s. n a. b T e notch-es. 11 6. and, 19 leave exposed. a Portion ofthe box hole edge so that the cable C may r t against d... xrcse l p n. and is gripped and, fastened thereby.

In assembling the box and, parts, the cable C is inserted through the box hole H with the two connecter parts oppositely lo,- cfli e lffihereby positioning the cable between the two parts. The clamp, screw 20 is set up. tightly against the cable G which serves to rigidly hold the two connecter parts, in position aswell. as. fasten the cable C to the sa c nne te p t The Single Screw net only anchors the connecter in the box hole by seating the box hole edge in the notches 16 and 19 but simultaneously fastensin the cable as well,

Referringv now. to Figures 6, 7. and 8, a substantially half-roundor arcuate stampn 2. s e e h m2 at. on n f rm Q b shing. a d s pu ched. c n r lly; oi orm r ove' pening h p 25 is inexpensive to manufacture by. virtue of itssimple design, and it is apparent how it is capable .of being cast or punched with economy. The punched or cast groove or slot 27 is placed over the box hole edge H thereby exposing an arc of the box edge within the inner circular wall of the shell 25. Since-the diameterof the shell 25 is less than that of the hole in the box, it follows that the box hole edge H is eccentrically exposed within the inner wall of the shell 25; Thus when a cable C is placed in the shell or cable rest 25 it is engaged by' the sharp projecting exposed edge H of the box 13..

A flat plate stamping 28 is punched with box hole edge notches 29 similar to the structure already described, there being two notches 29 formed in alignment and embracing the box wall B. A clamp screw 20, as already described, is carried by the plate 28 and is. directed toward the cable and preferably the plate may be curved or bent downwardly to cause the screw 20v to point at an angle towards. the box edge exposed in the cable rest 25 which more effectively pinches the cable wall G intothe sharp exposed arc of the box opening edge or rim,

' The-connecter parts 25 and 28 are placed diametrically opposite in the box hole H with, the cable C introduced therebetween, whereupon the screw 20 is driven downwardly against the cable which forces the cable-against the opening H exposed through the shell 25 thus rigidly anchoringall parts together,

It is apparent that I have produced a connecter which employs one operating means as. a screw to perform several func} tions namely, that of anchoring the connecter in the box hole, and that of fastening the cable in the connecter and box hole. Fur: thermore, the box hole edge itself is made to perform. several functions namely, that of gripping against the cable, and that of seating into'the connecter anchorage means.

hat I claim is:

1. Cable and box connecting meansv com-.

prising, a box having a cable and connecter receiving hole, a pair of connecter members disposed in the box hole and. including box hole edge receiving notches located substan tially at the center in onemember which notches engage and leave exposed the, box hole edge, and a screw threaded through one member to grip against a cable received be tween the members and to seat the notches of both members against the box hole edge and to force the cable against, the exposed box hole edge.

2. A connecter comprising. a pair of con,- necter members each of which includes box hole edge anchorage notches which leave exposed a box hole edge in theconnecter, and. a screw threaded through one connecter, member and directed towardthe other connecter member to grip a cable between the two members and against the exposed box hole edge.

3. A connecter comprising, separate connecter members adapted to fit into a box hole and including anchorage notches to receive the box hole edge, a screw threaded through one member and directed toward the other member, and a portion included at right angles on one member and extending toward the cable adjacent the notches.

4. A connecter comprising, a pair of separate members adapted to fit into a box hole and including anchorage notches to receive the box hole edge, a screw threaded through one member and directed toward the other member, and a portion included at substantially right angles on each member adjacent the notches and extending toward the cable, each portion being provided with a semicircular opening such that when placed together there is formed a cable receiving opening through the two portions.

In testimony whereof I afiix my signature.

JAMES C. LEDBETTER. v 

